Moved cache into separate caching package that is AOT compatible (#8255)

Author: michaelstaib

src/All.slnx

@@ -67,9 +67,11 @@
   <Folder Name="/HotChocolate/Caching/" />
   <Folder Name="/HotChocolate/Caching/src/">
     <Project Path="HotChocolate/Caching/src/Caching/HotChocolate.Caching.csproj" />
+    <Project Path="HotChocolate/Caching/src/Caching.Memory/HotChocolate.Caching.Memory.csproj" />
   </Folder>
   <Folder Name="/HotChocolate/Caching/test/">
     <Project Path="HotChocolate/Caching/test/Caching.Tests/HotChocolate.Caching.Tests.csproj" />
+    <Project Path="HotChocolate/Caching/test/Caching.Memory.Tests/HotChocolate.Caching.Memory.Tests.csproj" />
   </Folder>
   <Folder Name="/HotChocolate/Core/" />
   <Folder Name="/HotChocolate/Core/src/">

src/HotChocolate/Caching/HotChocolate.Caching.sln

@@ -0,0 +1,14 @@
+<Solution>
+  <Folder Name="/src/">
+    <Project Path="src/Caching/HotChocolate.Caching.csproj" />
+  </Folder>
+  <Folder Name="/src/Caching.Memory/">
+    <Project Path="src/Caching.Memory/HotChocolate.Caching.Memory.csproj" />
+  </Folder>
+  <Folder Name="/test/">
+    <Project Path="test/Caching.Tests/HotChocolate.Caching.Tests.csproj" />
+  </Folder>
+  <Folder Name="/test/Caching.Memory.Tests/">
+    <Project Path="test/Caching.Memory.Tests/HotChocolate.Caching.Memory.Tests.csproj" />
+  </Folder>
+</Solution>

src/HotChocolate/Caching/HotChocolate.Caching.slnx

@@ -1,15 +1,16 @@
 using System.Collections.Concurrent;
-using System.Diagnostics.Metrics;
 
-namespace HotChocolate.Utilities;
+namespace HotChocolate.Caching.Memory;
 
 /// <summary>
 /// The core cache implementation for the HotChocolate library.
 /// This cache uses a ring buffer to evict the least recently
 /// used entries when the cache is full.
 /// https://en.wikipedia.org/wiki/Page_replacement_algorithm#Clock
 /// </summary>
-/// <typeparam name="TValue"></typeparam>
+/// <typeparam name="TValue">
+/// The type of the value that is stored in the cache.
+/// </typeparam>
 public sealed class Cache<TValue>
 {
     private readonly int _capacity;
@@ -36,7 +37,7 @@ public sealed class Cache<TValue>
     /// </exception>
     public Cache(int capacity = 256, CacheDiagnostics? diagnostics = null)
     {
-        ArgumentOutOfRangeException.ThrowIfLessThan(capacity, 10);
+        ArgumentOutOfRangeException.ThrowIfLessThan(capacity, 1);
 
         _capacity = capacity;
         _ring = new CacheEntry[capacity];
@@ -232,14 +233,6 @@ private CacheEntry InsertNew(string key, TValue value)
         }
     }
 
-    /// <summary>
-    /// Clears all entries from the cache.
-    /// The clear might leave the cache in a dirty state.
-    /// This is acceptable as we are not using a clear in production.
-    /// It's more a helper for testing.
-    /// </summary>
-    public void Clear() => _map.Clear();
-
     /// <summary>
     /// Returns all keys in the cache. This method is for testing only.
     /// </summary>

src/HotChocolate/Utilities/src/Utilities/Cache.cs renamed to src/HotChocolate/Caching/src/Caching.Memory/Cache.cs

@@ -1,4 +1,4 @@
-namespace HotChocolate.Utilities;
+namespace HotChocolate.Caching.Memory;
 
 /// <summary>
 /// The diagnostics for the cache.

src/HotChocolate/Utilities/src/Utilities/CacheDiagnostics.cs renamed to src/HotChocolate/Caching/src/Caching.Memory/CacheDiagnostics.cs

@@ -0,0 +1,21 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <PackageId>HotChocolate.Caching.Memory</PackageId>
+    <AssemblyName>HotChocolate.Caching.Memory</AssemblyName>
+    <RootNamespace>HotChocolate.Caching.Memory</RootNamespace>
+    <NoWarn>HC8001;$(NoWarn)</NoWarn>
+  </PropertyGroup>
+
+  <PropertyGroup>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <IsAotCompatible>true</IsAotCompatible>
+    <NoWarn>$(NoWarn);CA1812</NoWarn>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <InternalsVisibleTo Include="HotChocolate.Caching.Memory.Tests" />
+  </ItemGroup>
+
+</Project>

src/HotChocolate/Caching/src/Caching.Memory/HotChocolate.Caching.Memory.csproj

@@ -1,4 +1,4 @@
-namespace HotChocolate.Utilities;
+namespace HotChocolate.Caching.Memory;
 
 internal sealed class NoOpCacheDiagnostics : CacheDiagnostics
 {

src/HotChocolate/Utilities/src/Utilities/NoOpCacheDiagnostics.cs renamed to src/HotChocolate/Caching/src/Caching.Memory/NoOpCacheDiagnostics.cs

@@ -1,10 +1,5 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
-  <ItemGroup>
-    <ProjectReference Include="..\..\..\Core\src\Execution\HotChocolate.Execution.csproj" />
-    <ProjectReference Include="..\..\..\Core\src\Types\HotChocolate.Types.csproj" />
-  </ItemGroup>
-
   <PropertyGroup>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
   </PropertyGroup>
@@ -22,6 +17,11 @@
     <InternalsVisibleTo Include="HotChocolate.Caching.Http.Tests" />
   </ItemGroup>
 
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\Core\src\Execution\HotChocolate.Execution.csproj" />
+    <ProjectReference Include="..\..\..\Core\src\Types\HotChocolate.Types.csproj" />
+  </ItemGroup>
+
   <ItemGroup>
     <PackageReference Include="Microsoft.Net.Http.Headers" />
   </ItemGroup>

src/HotChocolate/Caching/src/Caching/HotChocolate.Caching.csproj

@@ -1,6 +1,6 @@
 using Xunit;
 
-namespace HotChocolate.Utilities;
+namespace HotChocolate.Caching.Memory;
 
 public class CacheTests
 {
@@ -117,4 +117,100 @@ public void Evict_Items_That_Were_Not_Recently_Access_When_Cache_Is_Full()
             key => Assert.Equal("i", key),
             key => Assert.Equal("j", key));
     }
+
+    [Fact]
+    public void TryGet_Hit_IncrementsHitCounter()
+    {
+        var diag = new TestDiagnostics();
+        var cache = new Cache<int>(capacity: 16, diagnostics: diag);
+
+        cache.GetOrCreate("a", _ => 42); // first call = miss
+        Assert.True(cache.TryGet("a", out _)); // second call = hit
+
+        Assert.Equal(1, diag.Hits);
+        Assert.Equal(1, diag.Misses);
+        Assert.Equal(0, diag.Evictions);
+    }
+
+    [Fact]
+    public void GetOrCreate_HitVsMiss_CountsCorrectly()
+    {
+        var diag = new TestDiagnostics();
+        var cache = new Cache<int>(capacity: 8, diagnostics: diag);
+
+        // first request → miss
+        var v1 = cache.GetOrCreate("x", _ => 123);
+        // second request → hit
+        var v2 = cache.GetOrCreate("x", _ => 456);
+
+        Assert.Equal(123, v1);
+        Assert.Equal(123, v2); // the factory isn't called second time
+
+        Assert.Equal(1, diag.Misses);
+        Assert.Equal(1, diag.Hits);
+    }
+
+    [Fact]
+    public void Eviction_IsRecorded_WhenRingIsFull()
+    {
+        var diag = new TestDiagnostics();
+        var cache = new Cache<int>(capacity: 2, diagnostics: diag);
+
+        cache.GetOrCreate("a", _ => 1); // fill slot 0
+        cache.GetOrCreate("b", _ => 2); // fill slot 1
+        cache.GetOrCreate("c", _ => 3); // forces eviction of one entry
+
+        Assert.Equal(1, diag.Evictions);
+        Assert.Equal(2, cache.Count); // still limited by capacity
+    }
+
+    [Fact]
+    public void Gauges_ReportSizeAndCapacity()
+    {
+        var diag = new TestDiagnostics();
+        var cache = new Cache<string>(capacity: 4, diagnostics: diag);
+
+        cache.GetOrCreate("k1", _ => "x");
+        cache.GetOrCreate("k2", _ => "y");
+
+        Assert.NotNull(diag.SizeGauge);
+        Assert.NotNull(diag.CapacityGauge);
+
+        Assert.Equal(2, diag.SizeGauge!());
+        Assert.Equal(4, diag.CapacityGauge!());
+    }
+
+    [Fact]
+    public void TryGet_ReturnsFalse_WhenKeyIsAbsent()
+    {
+        var diag  = new TestDiagnostics();
+        var cache = new Cache<int>(capacity: 8, diagnostics: diag);
+
+        var found = cache.TryGet("unknown", out _);
+
+        Assert.False(found);
+        Assert.Equal(1, diag.Misses); // miss path recorded
+        Assert.Equal(0, diag.Hits);
+    }
+
+    private sealed class TestDiagnostics : CacheDiagnostics
+    {
+        public int Hits;
+        public int Misses;
+        public int Evictions;
+        public Func<long>? SizeGauge;
+        public Func<long>? CapacityGauge;
+
+        public override void Hit() => Hits++;
+
+        public override void Miss() => Misses++;
+
+        public override void Evict() => Evictions++;
+
+        public override void RegisterSizeGauge(Func<long> sizeProvider)
+            => SizeGauge = sizeProvider;
+
+        public override void RegisterCapacityGauge(Func<long> capacityProvider)
+            => CapacityGauge = capacityProvider;
+    }
 }

src/HotChocolate/Utilities/test/Utilities.Tests/CacheTests.cs renamed to src/HotChocolate/Caching/test/Caching.Memory.Tests/CacheTests.cs

@@ -0,0 +1,25 @@
+<Project Sdk="Microsoft.NET.Sdk" ToolsVersion="Current">
+
+  <PropertyGroup>
+    <AssemblyName>HotChocolate.Caching.Memory.Tests</AssemblyName>
+    <RootNamespace>HotChocolate.Caching.Memory</RootNamespace>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <None Update="$(MSBuildProjectDirectory)\__resources__\*.*">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+    <None Update="$(MSBuildProjectDirectory)\xunit.runner.json">
+      <CopyToOutputDirectory>Always</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\..\..\Core\src\Types.OffsetPagination\HotChocolate.Types.OffsetPagination.csproj" />
+    <ProjectReference Include="..\..\src\Caching.Memory\HotChocolate.Caching.Memory.csproj" />
+    <ProjectReference Include="..\..\src\Caching\HotChocolate.Caching.csproj" />
+    <ProjectReference Include="..\..\..\AspNetCore\src\AspNetCore\HotChocolate.AspNetCore.csproj" />
+    <ProjectReference Include="..\..\..\Core\test\Utilities\HotChocolate.Tests.Utilities.csproj" />
+  </ItemGroup>
+
+</Project>

src/HotChocolate/Caching/test/Caching.Memory.Tests/HotChocolate.Caching.Memory.Tests.csproj

@@ -1,5 +1,5 @@
 using System.Diagnostics.CodeAnalysis;
-using HotChocolate.Utilities;
+using HotChocolate.Caching.Memory;
 
 namespace HotChocolate.Authorization;
 
@@ -16,7 +16,4 @@ public bool TryGetDirectives(string documentId, [NotNullWhen(true)] out Authoriz
 
     public void TryAddDirectives(string documentId, AuthorizeDirective[] directives)
         => _cache.GetOrCreate(documentId, static (_, d) => d, directives);
-
-    public void Clear()
-        => _cache.Clear();
 }

src/HotChocolate/Core/src/Authorization/AuthorizationCache.cs

@@ -1,6 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
+using HotChocolate.Caching.Memory;
 using HotChocolate.Language;
-using HotChocolate.Utilities;
 
 namespace HotChocolate.Execution.Caching;
 
@@ -17,6 +17,4 @@ public void TryAddDocument(string documentId, CachedDocument document)
 
     public bool TryGetDocument(string documentId, [NotNullWhen(true)] out CachedDocument? document)
         => _cache.TryGet(documentId, out document);
-
-    public void Clear() => _cache.Clear();
 }

src/HotChocolate/Core/src/Execution/Caching/DefaultDocumentCache.cs

@@ -1,6 +1,6 @@
 using System.Diagnostics.CodeAnalysis;
+using HotChocolate.Caching.Memory;
 using HotChocolate.Execution.Processing;
-using HotChocolate.Utilities;
 
 namespace HotChocolate.Execution.Caching;
 
@@ -17,6 +17,4 @@ public void TryAddOperation(string operationId, IOperation operation)
 
     public bool TryGetOperation(string operationId, [NotNullWhen(true)] out IOperation? operation)
         => _cache.TryGet(operationId, out operation);
-
-    public void Clear() => _cache.Clear();
 }

src/HotChocolate/Core/src/Execution/Caching/DefaultPreparedOperationCache.cs

@@ -45,9 +45,4 @@ public interface IPreparedOperationCache
     /// The operation that shall be cached.
     /// </param>
     void TryAddOperation(string operationId, IOperation operation);
-
-    /// <summary>
-    /// Clears all items from the cache.
-    /// </summary>
-    void Clear();
 }

src/HotChocolate/Core/src/Execution/Caching/IPreparedOperationCache.cs

@@ -28,6 +28,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <ProjectReference Include="..\..\..\Caching\src\Caching.Memory\HotChocolate.Caching.Memory.csproj" />
     <ProjectReference Include="..\..\..\Utilities\src\Utilities.DependencyInjection\HotChocolate.Utilities.DependencyInjection.csproj" />
     <ProjectReference Include="..\Abstractions\HotChocolate.Abstractions.csproj" />
     <ProjectReference Include="..\Execution.Abstractions\HotChocolate.Execution.Abstractions.csproj" />

src/HotChocolate/Core/src/Execution/HotChocolate.Execution.csproj

@@ -1,4 +1,5 @@
 using System.Diagnostics.CodeAnalysis;
+using HotChocolate.Caching.Memory;
 using HotChocolate.Utilities;
 
 namespace HotChocolate.CostAnalysis.Caching;
@@ -18,6 +19,4 @@ public bool TryGetCostMetrics(
 
     public void TryAddCostMetrics(string operationId, CostMetrics costMetrics)
         => _cache.GetOrCreate(operationId, static (_, m) => m, costMetrics);
-
-    public void Clear() => _cache.Clear();
 }

src/HotChocolate/CostAnalysis/src/CostAnalysis/Caching/DefaultCostMetricsCache.cs

@@ -45,9 +45,4 @@ bool TryGetCostMetrics(
     void TryAddCostMetrics(
         string operationId,
         CostMetrics costMetrics);
-
-    /// <summary>
-    /// Clears all items from the cache.
-    /// </summary>
-    void Clear();
 }

src/HotChocolate/CostAnalysis/src/CostAnalysis/Caching/ICostMetricsCache.cs

@@ -1,4 +1,5 @@
 using System.Diagnostics.CodeAnalysis;
+using HotChocolate.Caching.Memory;
 using HotChocolate.CostAnalysis.Caching;
 using HotChocolate.Utilities;
 
@@ -39,6 +40,4 @@ public void TryAddCostMetrics(string operationId, CostMetrics costMetrics)
         _cache.GetOrCreate(operationId, static (_, m) => m, costMetrics);
         Additions++;
     }
-
-    public void Clear() => _cache.Clear();
 }